Demon8024 6 Posted May 20, 2021 Bought a 99 Foreman TRX450ES and was told that it needed top end (smoking bad) and the front diff (final drive) was broken. I got there and he said the ES wasn't working and he thought it was. Bike would start with a jump and smoked very badly surprised it even ran. Ended up buying the bike a little cheaper and getting it home. Once home I inspected it and then let it sit for a few weeks. First the battery was weak and having starting issues, added a new battery. Then on to the carb where it was clogged and dirty, cleaned and rebuilt carb with kit. Got it to fire finally and low and behold it still smoked a lot... Was told that he had it taken to a shop for new rings and piston (the shop told him the damage was pretty bad and it would only have a 40-50% chance not to smoke.) It smokes. filled shop in less than 30 sec. so rebuilt top end and found many loose bolts, exhaust was hanging on with a thread, and I'm shocked it wasn't blowing oil out of the head gaskets and base gaskets. once rebuilt put it back together it ran nice and smooth. Now to get it to move. Front diff was cracked and broken at the input shaft, bearing was non existent. Replaced with used junkyard diff, bought new CV axles both sides and front brakes. Finally ready to move it AND… ES doesn't work. I used manual foot shifting and rode it around the yard for about 20-30 mins. Went through all 5 gears and reverse, the screen had bad sun damage but I could see enough that everything seemed to work. When I press the button for up and down shifting on the ES controls nothing happens no noise no lights and no shifting. I have a Service manual I downloaded from the internet labeled as TRX450SFM.PDF. I followed the manual to the T and found nothing wrong with the ES system at the end of the trouble shooting steps it says if nothing wrong replace Shift control unit. Replaced with a used one ( being cheep) and still having the same problem. Now a side note is at the very beginning it says to make sure the Clutch is adjusted properly and on my bike the adjustment screw is seized in the case.. so I have yet to do that fearing stripping and case cracks etc. so that's what I'm left with and that's what I will be trying to do today. batt good and charges reads 12.2v this whole time check gears - Shifts fine no problems on all gears check relay - good check relay power (10v min) - 11.7v check relay continuity - Good check relay and control unit 5pin continuity - Good check 16pin control unit power (11v min) - 12v install jumper in CU and check power (11v min) - 12v check 5 pin CU for continuity - Good check 16 pin ohms (4-6 ohms) - 5ohms check 5 pin CU ohms (4.75-5.25) - 5 ohms visually inspect angle sensor - good check smooth ohms op on angle sensor - good check power on 3pin shift switch (4.75-5.25 volts) - 5volts inspect shift switch - good check shift switches for continuity - good check for continuity between 16pin CU and shift switch - good inspect gear position switch - Reverse and neutral have good continuity but 1st and 5th were reading with ohms and no continuity. plugged in and the HUD was reading all gear R, N ,1st,--,--,--,5th check continuity between gear position and 16 pin - good check shift motor with known good batt - Shifts both up and down and smooth replace Shift control unit - Replaced (with used from Ebay, assumed working but unsure will probably return) I have the 38910-HN0-A11 control unit Share this post Link to post Share on other sites
Tim-ANC 202 Posted May 20, 2021 Is it the screw or the locknut that is seized on the clutch adjuster? Suggest dousing it repeatedly with penetrant for a day. This wheeler sounds like it's been through !. Good job bringing her back to life. Share this post Link to post Share on other sites
Demon8024 6 Posted May 20, 2021 Thanks! The nut i was able to get it off. The adj screw is whats stuck. I have hit it will pb blast and try to turn it. And tried shifting with tension on the screw and its still stuck i will deff be useing more pb and go from there. Share this post Link to post Share on other sites
bcsman 1,404 Posted May 20, 2021 First congrats on what you have accomplished already with this 450, it does sound like it has been rode hard and put to bed wet....lol. So yes before anything else would be looked at for your shifting problem the clutch adjustment screw needs to be broken loose. It is hard to say how badly it is out of adjustment until you can move it. At the very worst scenario the front cover would need to come off to get at it. Share this post Link to post Share on other sites
Demon8024 6 Posted May 20, 2021 UPDATE Yes, so unfortunately I was impatient and was like I have the means I guess ill just pull the cover and check it out. it was very badly seized in the case. I ended up using a tool that when hit with a hammer it help spin out stuck bolts. it worked (for the most part) got the part off and messed up the external threads on the way out. so now I'm going to order a new adjustment screw and gasket for the clutch case. Of course after I got the case off, it looks like someone else was in there and put a new gasket on the old gasket instead of cleaning the old off. So... I have a bit of work to do and ill keep you posted. Thanks for all the help so far. Share this post Link to post Share on other sites
Tim-ANC 202 Posted May 20, 2021 Yeah, I get impatient some times too. Fortune favors the bold. Wow, sloppy on the gasket situation you found. Was it leaking? Share this post Link to post Share on other sites
shadetree 5,969 Posted May 21, 2021 i am going to toss in my .02's worth, and you can take it with a grain of salt. first : the clutch has NOTHING to do with why it will not shift, ever !. the clutch only keeps it from moving once it is in gear..that's all the clutch does..has NOTHING...AND I MEAN NOTHING TO DO WITH WHY IT WILL NOT SHIFT ?!. second: deff get the gasket taken care of, may as well replace the final shaft front out put oil seal while you have the front cover off..does it leak ?, maybe not ?, BUT NOW IS THE TIME TO REPLACE IT !. third: you need to test the shift motor to see if it is getting power while you have it out of the cover, plugged in, key on, hit the up or down buttons..does the shift motor move at all ?..if it does not ?, this very well could be a bad shift motor. DOES NOT MEAN IT IS THE SHIFT MOTOR ?, BUT IT DOES NARROW IT DOWN. if it does move when tested this way ?, then you need to inspect the electric shift transfer gears right there at the motor area, chances are , you either have a gear with bad teeth ?, or the shifting shaft splines are stripped out ?, either one..or both ?!. last but not least, very well can be a bad ground from battery ?, been there, done that. this should keep you busy for a min or two. please keep this thread updated , thanks !. 3 Share this post Link to post Share on other sites
Demon8024 6 Posted May 21, 2021 Testing the shift motor - the shift motor does not receive a signal from the Shift Control Unit. I unplugged the shift motor and tested with multimeter at the harness(motor plug) was not sending power through to the motor. I have also attached a 2nd battery (known good and charged) to the motor it will shift the bike up with the polarity one way, and when the polarity is reversed it will shift the bike down. The motor is good and working as it should. since I have taken the clutch cover off I will be doing the gasket correctly. I have inspected the shift motor gears already and they are in great shape. I do indeed agree with you about the clutch adjustment having nothing to do with the ES system. But with the manual saying to make sure it's adjusted correctly as first step before doing any other checks, it wont hurt me to go ahead and make that work properly. The ground you are talking about? would that be the motor ground or the frame ground? The motor ground is working fine since the bike fires right up (starter ground), but I have not inspected it. The frame ground is the same in that during the tests if I had no ground I would not get any voltage readings, but lass I have not inspected that as well. tomorrow I will be checking both grounds to double check thanks. Share this post Link to post Share on other sites
Fishfiles 20,147 Posted May 21, 2021 Welcome Demon to the forum , I have a couple of 450s myself , I'm not a ES guy , but if I was , I think I would be all over this gizmo :: https://hondaesshiftkit.com/products/98-04-honda-foreman-450-es/ 1 Share this post Link to post Share on other sites
shadetree 5,969 Posted May 21, 2021 10 hours ago, Demon8024 said: Testing the shift motor - the shift motor does not receive a signal from the Shift Control Unit. I unplugged the shift motor and tested with multimeter at the harness(motor plug) was not sending power through to the motor. I have also attached a 2nd battery (known good and charged) to the motor it will shift the bike up with the polarity one way, and when the polarity is reversed it will shift the bike down. The motor is good and working as it should. since I have taken the clutch cover off I will be doing the gasket correctly. I have inspected the shift motor gears already and they are in great shape. I do indeed agree with you about the clutch adjustment having nothing to do with the ES system. But with the manual saying to make sure it's adjusted correctly as first step before doing any other checks, it wont hurt me to go ahead and make that work properly. The ground you are talking about? would that be the motor ground or the frame ground? The motor ground is working fine since the bike fires right up (starter ground), but I have not inspected it. The frame ground is the same in that during the tests if I had no ground I would not get any voltage readings, but lass I have not inspected that as well. tomorrow I will be checking both grounds to double check thanks. great !. if shift motor does work with power straight to it like you did ?, then this tells me about 3 things, switch button on bars is bad ?, cpu/ecu/cdi/control unit is bad ?, or angle sensor is bad ?, or no power to connector to shift motor ( this is caused by one of the first two problems. 1 Share this post Link to post Share on other sites
Demon8024 6 Posted May 21, 2021 2 hours ago, Fishfiles said: Welcome Demon to the forum , I have a couple of 450s myself , I'm not a ES guy , but if I was , I think I would be all over this gizmo :: https://hondaesshiftkit.com/products/98-04-honda-foreman-450-es/ I was talking to one of my buddies about doing something similar to this. After looking at the bike and working on it, I was like I could just route the power straight to the motor. Share this post Link to post Share on other sites
shadetree 5,969 Posted May 21, 2021 1 hour ago, Demon8024 said: I was talking to one of my buddies about doing something similar to this. After looking at the bike and working on it, I was like I could just route the power straight to the motor. you could, but you will need a two-way rocker switch to change the polarity of the power source to make the shift motor go both ways. this is what the buttons on the bars do. Share this post Link to post Share on other sites
freebo86 291 Posted May 21, 2021 Take the shift motor out, and bench test it. Apply 12V from the battery to 2 of the 3 leads. Check the Wiring Diagram from the Service Manual which ones are the + and - (upshift). To reverse the operation of the shift motor flip + & - (mimics the downshift). This will tell you if the motor even engages and spins the shaft. If it does, move onto the next test point. If no movement from Shift Motor then you need a new one. 1 Share this post Link to post Share on other sites
Demon8024 6 Posted May 21, 2021 33 minutes ago, freebo86 said: Take the shift motor out, and bench test it. Apply 12V from the battery to 2 of the 3 leads. Check the Wiring Diagram from the Service Manual which ones are the + and - (upshift). To reverse the operation of the shift motor flip + & - (mimics the downshift). This will tell you if the motor even engages and spins the shaft. If it does, move onto the next test point. If no movement from Shift Motor then you need a new one. Ive done that it shifts fine Share this post Link to post Share on other sites
freebo86 291 Posted May 21, 2021 (edited) 25 minutes ago, Demon8024 said: Ive done that it shifts fine The motor engages? Well then I'd move and check your switches see if they send signals (continuity) downstream. I do not really know where the Up/Down switch sends it's signal but find the end and ensure the switch actually works. if it also works, then your fault is at whatever they are tied into. I'm sure @retro will chime in here shortly. There was a guy just the other day had shifting issues and there is troubleshooting steps posted in his thread. Ignore the "Wont start" in his title, his thread turns into a shifting issue as you read through it. Edited May 21, 2021 by freebo86 1 Share this post Link to post Share on other sites
Demon8024 6 Posted May 26, 2021 Update: got the parts in put the new clutch adj screw in and put bike back together. I bought the bypass harness as mentioned above. buke run and shifts great thanks everyone for your help. 6 Share this post Link to post Share on other sites
Fishfiles 20,147 Posted August 23, 2021 On 5/26/2021 at 7:07 AM, Demon8024 said: Update: got the parts in put the new clutch adj screw in and put bike back together. I bought the bypass harness as mentioned above. buke run and shifts great thanks everyone for your help. Wow , good deal @Demon8024 , I missed this post back in May --- that by-pass harness is the way to go for ES problems , pretty much for the price of a angle sensor it can be fixed as long as your shift motor is OK Share this post Link to post Share on other sites